首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5245篇
  免费   284篇
  国内免费   2篇
  2024年   12篇
  2023年   80篇
  2022年   93篇
  2021年   129篇
  2020年   170篇
  2019年   183篇
  2018年   274篇
  2017年   284篇
  2016年   252篇
  2015年   153篇
  2014年   180篇
  2013年   659篇
  2012年   378篇
  2011年   384篇
  2010年   249篇
  2009年   132篇
  2008年   319篇
  2007年   247篇
  2006年   250篇
  2005年   173篇
  2004年   138篇
  2003年   103篇
  2002年   99篇
  2001年   45篇
  2000年   76篇
  1999年   46篇
  1998年   26篇
  1997年   21篇
  1996年   18篇
  1995年   14篇
  1994年   20篇
  1993年   16篇
  1992年   23篇
  1991年   22篇
  1990年   25篇
  1989年   23篇
  1988年   14篇
  1987年   18篇
  1986年   9篇
  1985年   14篇
  1983年   9篇
  1982年   8篇
  1981年   10篇
  1974年   9篇
  1973年   11篇
  1971年   12篇
  1969年   7篇
  1968年   13篇
  1966年   8篇
  1965年   8篇
排序方式: 共有5531条查询结果,搜索用时 15 毫秒
121.
This study examined predictors of anxiety symptomatology among immigrant Mexican migrant farmworkers in the Midwest. Its purposes were to assess the prevalence of anxiety symptoms, to examine the relationship between acculturative stress and anxiety, and to determine the variables that best predict anxiety. Heightened levels were found for overall anxiety and in the cognitive, affective, and physiological expressions of anxiety. Elevated acculturative stress, low self-esteem, ineffective social support, lack of control and choice in living a migrant farmworker lifestyle, low religiosity, and high education were significantly related to high anxiety. Findings suggest that migrant farmworkers who experience elevated acculturative stress are susceptible to the development of anxiety-related disorders and highlight the importance of establishing prevention and treatment services for migrant farmworkers.  相似文献   
122.
Bimbó  Katalin 《Studia Logica》2000,66(2):285-296
Combinatory logic is known to be related to substructural logics. Algebraic considerations of the latter, in particular, algebraic considerations of two distinct implications (, ), led to the introduction of dual combinators in Dunn & Meyer 1997. Dual combinators are "mirror images" of the usual combinators and as such do not constitute an interesting subject of investigation by themselves. However, when combined with the usual combinators (e.g., in order to recover associativity in a sequent calculus), the whole system exhibits new features. A dual combinatory system with weak equality typically lacks the Church-Rosser property, and in general it is inconsistent. In many subsystems terms "unexpectedly" turn out to be weakly equivalent. The paper is a preliminary attempt to investigate some of these issues, as well as, briefly compare function application in symmetric -calculus (cf. Barbanera & Berardi 1996) and dual combinatory logic.  相似文献   
123.
A comparative analysis was conducted of five different methods for scoring the Rod-and-Frame Test to examine the convergent validities of each of the five methods with performance on the Embedded Figures Test for a sample of 408 13- to 16-yr.-olds. The scoring methods included the absolute error, the algebraic error, the absolute value of the algebraic error, the frame effect, and an assessment of relative field dependence. Correlations obtained among the five methods and the Embedded Figures Test indicated different patterns for boys and girls. In general, the method which employed the absolute value of the algebraic error yielded the strongest convergent validity coefficients with scores on the Embedded Figures Test and Group Embedded Figures Test for boys (.62 and -.54, respectively), although, for girls, the absolute algebraic error and absolute error both yielded coefficients of .50 with Embedded Figures Test scores and -.46 with Group Embedded Figures Test scores.  相似文献   
124.
We examined whether the functionality of spatial relations affects the construction and memory of information in situation models. A functional relationship involves the interaction of entities that is implied by either typical use or contextual demands. Previous research has shown that spatial relations are less likely to be encoded during comprehension unless there is extensive prior knowledge, explicit instructions to attend to spatial information, or a clear emphasis on spatial information. If the construction of a situation model is guided by a need to understand the functional structure of a situation, then functional spatial relations should be more likely to be encoded. The results of our study showed that sentences with functional spatial relations were read faster and remembered better in both recall and recognition tests than sentences with nonfunctional spatial relations.  相似文献   
125.
Current general health belief measures that are used to assess health behaviors do not capture the full range of health beliefs present among Latinos. The purpose of this study was to develop a reliable and valid measure of Latino health beliefs, the Cultural Health Attributions Questionnaire (CHAQ). Three hundred forty participants were recruited in 2 metropolitan areas with large Latino populations. Exploratory factor analysis revealed 2 highly interpretable 12-item subscales: the Equity Attribution and the Behavioral-Environmental Attribution scales. Examination of the relationships between the subscales and measures of acculturation provided evidence of construct validity. Moreover, the prediction of health care behavior by the CHAQ also indicated initial criterion validity.  相似文献   
126.
Attention and joint attention in preschool children with autism   总被引:13,自引:0,他引:13  
Three experiments examined the role of attention in explaining dyadic (child-adult) and triadic (child-adult-object) joint attention difficulties in autism. Experiments 1 and 2 investigated children's ability to orient to an adult's attention bid and to follow the direction of a human or nonhuman cue. Experiment 3 tested ability to disengage and shift attention to objects. Results showed autism-specific difficulties at both dyadic and triadic levels. Children with autism were less responsive than developmentally delayed controls in orienting to attention bids and in following a human head-turn cue yet had no difficulty in shifting attention and were faster overall in orienting to targets. Results suggest a specific developmental delay in which children with autism rely on the presence of objects in the visual field to guide action. The relation between this problem and autistic children's difficulties with human communicative signals is discussed.  相似文献   
127.
The processing of transparent Finnish compound words was investigated in 2 experiments in which eye movements were recorded while sentences were read silently. The frequency of the second constituent had a large influence (95 ms) on gaze duration on the target words, but its influence was relatively late in processing: A clear effect only occurred on the probability of a third fixation. The frequency of the whole compound word had a similar influence on gaze duration (82 ms) and influenced eye movements at least as rapidly as did the frequency of the second constituent. These results, together with an earlier finding that the frequency of the first constituent affected the first fixation duration, indicate that the identification of these compound words involves parallel processing of both morphological constituents and whole-word representations.  相似文献   
128.
The development of object permanence was investigated in black-billed magpies (Pica pica), a food-storing passerine bird. The authors tested the hypothesis that food-storing development should be correlated with object-permanence development and that specific stages of object permanence should be achieved before magpies become independent. As predicted, Piagetian Stages 4 and 5 were reached before independence was achieved, and the ability to represent a fully hidden object (Piagetian Stage 4) emerged by the age when magpies begin to retrieve food. Contrary to psittacine birds and humans, but as in dogs and cats, no "A-not-B error" occurred. Although magpies also mastered 5 of 6 invisible displacement tasks, evidence of Piagetian Stage 6 competence was ambiguous.  相似文献   
129.
Tre: Wstp. I. Definicje arbitralne. II. Syntetyczne konsekwencje definicji arbitralnych III. Analityczne i rzeczowe komponenty definicji arbitralnych. IV. Zdania analityczne.Artyku ten w nieznacznym tylko stopniu róni si od pracy doktorskiej, któr przedstawiem w 1962 r. Jak najuprzejmiej dzikuj Prof. Dr M. Kokoszyskiej-Lutman, Prof. Dr J. Supeckiemu oraz Doc. Dr M. Przeckiemu za szereg uwag i wskazówek, z których tak wiele skorzystaem przygotowujc ostateczn redakcj pracy.  相似文献   
130.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号